Answer
$(-\infty, -2)$
Refer to the image below for the graph.
Work Step by Step
Subtract $11$ on both sides to obtain:
$3x \lt -6$
Divide by $3$ on both sides to obtain:
$x \lt -2$
The solution set is the set of real numbers less than $-2$.
In interval notation, the solution set is:
$(-\infty, -2)$
To graph this inequality, plot a hole (or hollow dot) at $x=-2$ then shade the region to its left.
(refer to the attached image in the answer part)